package main

import (
	"flag"
	"fmt"
	"log"
	"os"
	"os/signal"
	"path/filepath"
	"runtime"
	"runtime/pprof"
	"strconv"
	"strings"
	"syscall"
	"time"

	"git.stormux.org/storm/skald/diskwriter"
	"git.stormux.org/storm/skald/hall"
	"git.stormux.org/storm/skald/ice"
	"git.stormux.org/storm/skald/limit"
	"git.stormux.org/storm/skald/token"
	"git.stormux.org/storm/skald/turnserver"
	"git.stormux.org/storm/skald/webserver"
)

func main() {
	var cpuprofile, memprofile, mutexprofile, httpAddr string
	var udpRange string

	flag.StringVar(&httpAddr, "http", ":8443", "web server `address`")
	flag.StringVar(&webserver.StaticRoot, "static", "./static/",
		"web server root `directory`")
	flag.BoolVar(&webserver.Insecure, "insecure", false,
		"act as an HTTP server rather than HTTPS")
	flag.StringVar(&hall.DataDirectory, "data", "./data/",
		"data `directory`")
	flag.StringVar(&hall.Directory, "halls", "./halls/",
		"hall description `directory`")
	flag.StringVar(&diskwriter.Directory, "recordings", "./recordings/",
		"recordings `directory`")
	flag.StringVar(&cpuprofile, "cpuprofile", "",
		"store CPU profile in `file`")
	flag.StringVar(&memprofile, "memprofile", "",
		"store memory profile in `file`")
	flag.StringVar(&mutexprofile, "mutexprofile", "",
		"store mutex profile in `file`")
	flag.StringVar(&udpRange, "udp-range", "",
		"UDP `port` (multiplexing) or port1-port2 (range)")
	flag.BoolVar(&hall.UseMDNS, "mdns", false, "gather mDNS addresses")
	flag.BoolVar(&ice.ICERelayOnly, "relay-only", false,
		"require use of TURN relays for all media traffic")
	flag.StringVar(&turnserver.Address, "turn", "auto",
		"built-in TURN server `address` (\"\" to disable)")
	flag.Parse()

	if udpRange != "" {
		if strings.ContainsRune(udpRange, '-') {
			var min, max uint16
			n, err := fmt.Sscanf(udpRange, "%v-%v", &min, &max)
			if err != nil || n != 2 {
				log.Fatalf("UDP range: %v", err)
			}
			if n != 2 || min <= 0 || max <= 0 || min > max {
				log.Fatalf("UDP range: bad range")
			}
			hall.UDPMin = min
			hall.UDPMax = max
		} else {
			port, err := strconv.Atoi(udpRange)
			if err != nil {
				log.Fatalf("UDP: %v", err)
			}
			err = hall.SetUDPMux(port)
			if err != nil {
				log.Fatalf("UDP: %v", err)
			}
		}
	}

	if cpuprofile != "" {
		f, err := os.Create(cpuprofile)
		if err != nil {
			log.Printf("Create(cpuprofile): %v", err)
			return
		}
		pprof.StartCPUProfile(f)
		defer func() {
			pprof.StopCPUProfile()
			f.Close()
		}()
	}

	if memprofile != "" {
		defer func() {
			f, err := os.Create(memprofile)
			if err != nil {
				log.Printf("Create(memprofile): %v", err)
				return
			}
			pprof.WriteHeapProfile(f)
			f.Close()
		}()
	}

	if mutexprofile != "" {
		runtime.SetMutexProfileFraction(1)
		defer func() {
			f, err := os.Create(mutexprofile)
			if err != nil {
				log.Printf("Create(mutexprofile): %v", err)
				return
			}
			pprof.Lookup("mutex").WriteTo(f, 0)
			f.Close()
		}()
	}

	n, err := limit.Nofile()
	if err != nil {
		log.Printf("Couldn't get file descriptor limit: %v", err)
	} else if n < 0xFFFF {
		log.Printf("File descriptor limit is %v, please increase it!", n)
	}

	ice.ICEFilename = filepath.Join(hall.DataDirectory, "ice-servers.json")
	token.SetStatefulFilename(
		filepath.Join(
			filepath.Join(hall.DataDirectory, "var"),
			"tokens.jsonl",
		),
	)

	// make sure the list of public halls is updated early
	go hall.Update()

	// causes the built-in server to start if required
	ice.Update()
	defer turnserver.Stop()

	err = webserver.Serve(httpAddr, hall.DataDirectory)
	if err != nil {
		log.Fatalf("Server: %v", err)
	}

	terminate := make(chan os.Signal, 1)
	signal.Notify(terminate, syscall.SIGINT, syscall.SIGTERM)

	go relayTest()

	ticker := time.NewTicker(15 * time.Minute)
	defer ticker.Stop()

	slowTicker := time.NewTicker(12 * time.Hour)
	defer slowTicker.Stop()

	for {
		select {
		case <-ticker.C:
			go func() {
				hall.Update()
				token.Expire()
				cleanupRecordings()
			}()
		case <-slowTicker.C:
			go relayTest()
		case <-terminate:
			webserver.Shutdown()
			return
		}
	}
}

func cleanupRecordings() {
	conf, err := hall.GetConfiguration()
	if err != nil {
		log.Printf("Recording cleanup: %v", err)
		return
	}
	if conf.RecordingRetention == "" {
		return
	}
	retention, err := time.ParseDuration(conf.RecordingRetention)
	if err != nil {
		log.Printf("Recording cleanup: bad recordingRetention %q: %v",
			conf.RecordingRetention, err)
		return
	}
	if retention <= 0 {
		return
	}
	if err := diskwriter.CleanupOldRecordings(retention); err != nil {
		log.Printf("Recording cleanup: %v", err)
	}
}

func relayTest() {
	now := time.Now()
	d, err := ice.RelayTest(20 * time.Second)
	if err != nil {
		log.Printf("Relay test failed: %v", err)
		log.Printf("Perhaps you didn't configure a TURN server?")
		return
	}
	log.Printf("Relay test successful in %v, RTT = %v", time.Since(now), d)
}